This invention relates to a circular knitting machine incorporating a stitch density adjuster device, and in particular, to a circular hose-knitting machine.
As is known this adjustment is performed by shifting the needle cylinder vertically with respect to the stitch formation plane, and hence, to the cam assemblies, to obtain longer or shorter stitches. The cylinder, which is displaceable axially to the cylinder holder, bears by means of bearing rods on a thrust bearing, in turn supported on a forked end of a lever. This lever is journalled to the stationary structure of the machine and has an opposite end which abuts an intermediate part of an adjustment rod, journalled at one end to the stationary part of the machine and abuts at the other end thereof against a stationary part of the machine. The rod is displaceable out of its rest position by the action of levers which are driven by cams provided on the machine main drum.
Thus, the elevation of the needle cylinder can be adjusted as well as the stitch density as the main drum rotates progressively.
These devices have the disadvantage of being mechanically complicated in that several drive and lay levers are to be arranged.
Another disadvantage is that these machines are very laborious to tune-up and adjust, owing to the presence of many mechanical members, so that the operation requires much time if it is to provide reliable results. Furthermore, with multi-feed machines, where the machine is to operate at different densities between the feed, one must manipulate adjustment screws provided at each feed.